/*!	 metaballs.cpp
**	 Implementation of the "Metaballs" layer
**
**	Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
**	Copyright (c) 2012-2013 Carlos López
**
**	This package is free software; you can redistribute it and/or
**	modify it under the terms of the GNU General Public License as
**	published by the Free Software Foundation; either version 2 of
**	the License, or (at your option) any later version.
**
**	This package is distributed in the hope that it will be useful,
**	but WITHOUT ANY WARRANTY; without even the implied warranty of
**	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
**	General Public License for more details.
**
*/

#ifdef USING_PCH
#	include "pch.h"
#else
#ifdef HAVE_CONFIG_H
#	include <config.h>
#endif

#include <synfig/localization.h>
#include <synfig/general.h>

#include <synfig/string.h>
#include <synfig/time.h>
#include <synfig/context.h>
#include <synfig/paramdesc.h>
#include <synfig/renddesc.h>
#include <synfig/surface.h>
#include <synfig/value.h>
#include <synfig/valuenode.h>
#include <ETL/pen>

#include "metaballs.h"

#endif

using namespace etl;
using namespace std;
using namespace synfig;

SYNFIG_LAYER_INIT(Metaballs);
SYNFIG_LAYER_SET_NAME(Metaballs, "metaballs");
SYNFIG_LAYER_SET_LOCAL_NAME(Metaballs, N_("Metaballs"));
SYNFIG_LAYER_SET_CATEGORY(Metaballs, N_("Example"));
SYNFIG_LAYER_SET_VERSION(Metaballs, "0.1");
SYNFIG_LAYER_SET_CVS_ID(Metaballs, "$Id$");

Metaballs::Metaballs():
    Layer_Composite(1.0, Color::BLEND_COMPOSITE),
    param_gradient(ValueBase(Gradient(Color::black(), Color::white()))),
    param_centers(ValueBase(std::vector<synfig::Point>())),
    param_radii(ValueBase(std::vector<synfig::Real>())),
    param_weights(ValueBase(std::vector<synfig::Real>())),
    param_threshold(ValueBase(Real(0))),
    param_threshold2(ValueBase(Real(1))),
    param_positive(ValueBase(false))
{
    std::vector<synfig::Point> centers;
    std::vector<synfig::Real> radii;
    std::vector<synfig::Real> weights;
    centers.push_back(Point(0, -1.5));
    radii.push_back(2.5);
    weights.push_back(1);
    centers.push_back(Point(-2,  1));
    radii.push_back(2.5);
    weights.push_back(1);
    centers.push_back(Point(2,  1));
    radii.push_back(2.5);
    weights.push_back(1);
    param_centers.set_list_of(centers);
    param_radii.set_list_of(radii);
    param_weights.set_list_of(weights);

    SET_INTERPOLATION_DEFAULTS();
    SET_STATIC_DEFAULTS();
}

bool
Metaballs::set_param(const String & param, const ValueBase &value)
{
    IMPORT_VALUE(param_centers);
    IMPORT_VALUE(param_radii);
    IMPORT_VALUE(param_weights);
    IMPORT_VALUE(param_gradient);
    IMPORT_VALUE(param_threshold);
    IMPORT_VALUE(param_threshold2);
    IMPORT_VALUE(param_positive);

    return Layer_Composite::set_param(param, value);
}

ValueBase
Metaballs::get_param(const String &param)const
{
    EXPORT_VALUE(param_gradient);
    EXPORT_VALUE(param_radii);
    EXPORT_VALUE(param_weights);
    EXPORT_VALUE(param_centers);
    EXPORT_VALUE(param_threshold);
    EXPORT_VALUE(param_threshold2);
    EXPORT_VALUE(param_positive);

    EXPORT_NAME();
    EXPORT_VERSION();

    return Layer_Composite::get_param(param);
}

Layer::Vocab
Metaballs::get_param_vocab()const
{
    Layer::Vocab ret(Layer_Composite::get_param_vocab());

    ret.push_back(ParamDesc("gradient")
                  .set_local_name(_("Gradient"))
                 );

    ret.push_back(ParamDesc("centers")
                  .set_local_name(_("Balls"))
                 );

    ret.push_back(ParamDesc("radii")
                  .set_local_name(_("Radii"))
                 );

    ret.push_back(ParamDesc("weights")
                  .set_local_name(_("Weights"))
                 );

    ret.push_back(ParamDesc("threshold")
                  .set_local_name(_("Gradient Left"))
                 );

    ret.push_back(ParamDesc("threshold2")
                  .set_local_name(_("Gradient Right"))
                 );

    ret.push_back(ParamDesc("positive")
                  .set_local_name(_("Positive Only"))
                 );

    return ret;
}

synfig::Layer::Handle
Metaballs::hit_check(synfig::Context context, const synfig::Point &point)const
{
    Real density(totaldensity(point));

    if (density <= 0 || density > 1 || get_amount() == 0) {
        return context.hit_check(point);
    }

    synfig::Layer::Handle tmp;

    if (get_blend_method() == Color::BLEND_BEHIND && (tmp = context.hit_check(point))) {
        return tmp;
    }

    if (Color::is_onto(get_blend_method()) && !(context.hit_check(point))) {
        return 0;
    }

    return const_cast<Metaballs*>(this);
}

Real
Metaballs::densityfunc(const synfig::Point &p, const synfig::Point &c, Real R)const
{
    bool positive = param_positive.get(bool());

    const Real dx = p[0] - c[0];
    const Real dy = p[1] - c[1];

    const Real n = (1 - (dx * dx + dy * dy) / (R * R));

    if (positive && n < 0) {
        return 0;
    }

    return (n * n * n);


}

Real
Metaballs::totaldensity(const Point &pos)const
{
    std::vector<synfig::Point> centers(param_centers.get_list_of(synfig::Point()));
    std::vector<synfig::Real> radii(param_radii.get_list_of(synfig::Real()));
    std::vector<synfig::Real> weights(param_weights.get_list_of(synfig::Real()));
    synfig::Real threshold = param_threshold.get(Real());
    synfig::Real threshold2 = param_threshold2.get(Real());

    Real density = 0;

    // sum up weighted functions
    for (unsigned int i = 0; i < centers.size(); i++) {
        density += weights[i] * densityfunc(pos, centers[i], radii[i]);
    }

    return (density - threshold) / (threshold2 - threshold);
}

Color
Metaballs::get_color(Context context, const Point &pos)const
{
    Gradient gradient = param_gradient.get(Gradient());

    if (get_amount() == 1.0 && get_blend_method() == Color::BLEND_STRAIGHT) {
        return gradient(totaldensity(pos));
    } else {
        return Color::blend(gradient(totaldensity(pos)), context.get_color(pos), get_amount(), get_blend_method());
    }
}

CairoColor
Metaballs::get_cairocolor(Context context, const Point &pos)const
{
    Gradient gradient = param_gradient.get(Gradient());

    if (get_amount() == 1.0 && get_blend_method() == Color::BLEND_STRAIGHT) {
        return CairoColor(gradient(totaldensity(pos)));
    } else {
        return CairoColor::blend(CairoColor(gradient(totaldensity(pos))), context.get_cairocolor(pos), get_amount(), get_blend_method());
    }
}

bool
Metaballs::accelerated_render(Context context, Surface *surface, int quality, const RendDesc &renddesc, ProgressCallback *cb)const
{
    RENDER_TRANSFORMED_IF_NEED(__FILE__, __LINE__)

    Gradient gradient = param_gradient.get(Gradient());

    // Width and Height of a pixel
    const Point  tl(renddesc.get_tl());
    const int 	 w(renddesc.get_w()), 	h(renddesc.get_h());
    const Real	pw(renddesc.get_pw()), ph(renddesc.get_ph());

    SuperCallback supercb(cb, 0, 9000, 10000);

    Point pos(tl[0], tl[1]);

    if (!context.accelerated_render(surface, quality, renddesc, &supercb)) {
        if (cb) {
            cb->error(strprintf(__FILE__"%d: Accelerated Renderer Failure", __LINE__));
        }

        return false;
    }

    for (int y = 0; y < h; y++, pos[1] += ph) {
        pos[0] = tl[0];

        for (int x = 0; x < w; x++, pos[0] += pw) {
            (*surface)[y][x] = Color::blend(gradient(totaldensity(pos)), (*surface)[y][x], get_amount(), get_blend_method());
        }
    }

    // Mark our progress as finished
    if (cb && !cb->amount_complete(10000, 10000)) {
        return false;
    }

    return true;
}